5.1 Universal Law of Gravitation  Summary and Q&A
TL;DR
Objects in space are mutually attracted to each other due to gravitational force, which is proportional to their masses and the square of the distance between them.
Key Insights
 👾 The universal law of gravitation is based on the mutual attraction between two objects in space due to gravitational force.
 ❎ The force of gravity is directly proportional to the product of the masses of the objects and inversely proportional to the square of the distance between them.
 🇦🇪 The direction of the gravitational force is given by the unit vector in the radial direction between the objects.
 👮 Newton's third law holds true in the context of the universal law of gravitation, with equal and opposite forces between the objects.
 ♊ The gravitational constant, denoted as G, is a proportionality constant that determines the strength of the gravitational force.
 🤒 The units for gravitational force are Newton (N), mass is measured in kilograms (kg), and distance in meters (m).
 👾 The formula for the gravitational force can be used to calculate the force between any two objects in space.
Transcript
The motion of objects in space is governed by the universal law of gravity. So let's consider how this works. We have two objects here, object one and two. And that could be two planets or two asteroids or two white dwarfs, black holes, any kind of objects you can imagine. And they are mutually attracted by each other due to gravitation. So we have... Read More
Questions & Answers
Q: What is the universal law of gravitation?
The universal law of gravitation states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
Q: How is the gravitational force between two objects calculated?
The gravitational force between two objects is calculated using the formula F = G * (m1 * m2) / r^2, where F is the force, G is the gravitational constant, m1 and m2 are the masses of the objects, and r is the distance between them.
Q: What is the significance of the unit vector in the gravitational force equation?
The unit vector, denoted as rhat, gives the direction of the force. It is chosen to point radially from one object to the other, representing the direction of attraction between them.
Q: How does Newton's third law apply to the universal law of gravitation?
Newton's third law, which states that every action has an equal and opposite reaction, applies to the universal law of gravitation. The force between two objects is equal in magnitude but opposite in direction, satisfying Newton's third law.
Summary & Key Takeaways

The universal law of gravitation governs the motion of objects in space and is based on the mutual attraction between them.

The force of gravity between two objects is proportional to the product of their masses and inversely proportional to the square of the distance between them.

The direction of the gravitational force is given by the unit vector in the radial direction between the objects.